Z-score Practice

Front

What is a Z-score?

Back

A Z-score indicates how many standard deviations an element is from the mean. It is calculated using the formula: Z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

How do you calculate a Z-score?

Back

To calculate a Z-score, use the formula: Z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

What does a positive Z-score indicate?

Back

A positive Z-score indicates that the value is above the mean.

Front

What does a negative Z-score indicate?

Back

A negative Z-score indicates that the value is below the mean.

Front

If the mean is 22 and the standard deviation is 3.1, what is the Z-score for x = 29?

Back

Z = (29 - 22) / 3.1 = 2.26.

Front

If Z-score = -1.25, standard deviation = 4, and x = 11, what is the mean?

Back

Mean = x - (Z * σ) = 11 - (-1.25 * 4) = 16.

Front

What is the Z-score for a waist size of 33 inches if the mean is 29 inches and the standard deviation is 2 inches?

Back

Z = (33 - 29) / 2 = 2.

Front

If the mean is 21 and the standard deviation is 1.3, what is the Z-score for x = 22?

Back

Z = (22 - 21) / 1.3 = 0.77.

Front

What is the formula to find the original score from a Z-score?

Back

Original Score = μ + (Z * σ).

Front

If Jane's Z-score is 1.20 on a test with a mean of 100 and a standard deviation of 15, what was her score?

Back

Score = 100 + (1.20 * 15) = 118.